Implement the runtime execution engine for validation tool wrapping,
as specified in docs/specification.md § Tool Wrapping.
WrappedToolExecutor resolves wraps references and delegates execution
to wrapped tools, supporting composable wrapping chains with cycle
detection and depth limiting (max 10 levels).
ArgumentMapper translates arguments between wrapper and wrapped tool
schemas using the argument_mapping configuration. Supports both
forwarded parameter names and literal fixed values.
TransformExecutor runs user-supplied transform functions in a
sandboxed Python environment with restricted builtins (no imports,
no filesystem, no network access). Validates that transforms return
proper validation-format dicts with a passed boolean.
Wired into the tool package public API via tool/__init__.py exports.
All new error types (WrappedToolNotFoundError, WrappingCycleError,
WrappingDepthExceededError, TransformExecutionError) provide clear
diagnostic messages.
Tests: 20 Behave scenarios covering argument mapping, transform
execution, simple/chained delegation, error handling, and sandbox
restrictions. 8 Robot Framework integration smoke tests. ASV
benchmarks for delegation overhead measurement.
ISSUES CLOSED: #543
